Process of testing textiles.



H. L. SCOTT.

PROCESS OF TESTING TEXTILES. APPLICATION FILED JAN. 9. 19x5.

. Patented May 23, 1916 28 27 E a." 3 a 1 i 90 J" m 25 4 g 1 30 32 33 a I i Q 23 5 \2/ I /9 I 3/ 4 mvemlfoz aw/knew: 23 7 9-3 I $0032 UNITED STATES PATENT OFFICE.

HENRY L SC'OTT, OF'PROVIDENGE, RHODE ISLAND.

PROCESS OF TESTING TEXTILES.

Application filed January 9, 1915. Serial No. 1,461.

method or process of testing the tensile. strength of fabric 'or other material which consists in placing a strip of the material to be tested under tension, then cutting the opposite edges of the same, reducing the effective termined dimension, and then continue to increase the strain until rupture takes place, an exhibitor beingconnected to the testing apparatus so that the exact breaking strain may be readily ascertained.

In the accompanying drawings: Figure 1 is a side elevat on partlv in section showing one form of testing machine to.

which my improved device is shown as being attached. partly in section showing one form of severing device and a portion 'of the means whereby it may be attached to the. tension applying machine. Fig. 3- is a perspective view showing the gripping jaws engaging opposite ends of the narrow strip of fabric and representing a strip as having been pulled apart also showingthe sever- .ing device inposition to operate upon a strip held between the jaws. Fig. 4-- represents a strip of material with its opposite length and edges cut inward a predetermined depth.

The usual method of testing woven fabrics such as cloth, canvas and the like, is to strip the material into narrow widths, usually about one inch wide and then apply a strain to the strip sufficient to pull the fabric apart, but'lt is found that such a test is quite unsatisfactory, particularly with the heavier fabrics such as canvasduck or the like, for the reason warp threads are passed alternately over and under the weft threads and arethus formed in a wavy or sinuous line, which naturally takes up considerable of their when such'a fabric is placed under tension the first two or three threads at the opposite edges of the strip which are practically released bythe severedfilling threads, straighten out, and thus fail to support their proportion of the load, and therefore by Specification of Letters latent.

load resisting portion to a prede- Fig. 2 is a side elevation that in weaving, the.

Patented May 2 3, 1916.

this means a fair test of .the strength of the one inch of fabric cannot possibly be obtained. To obviate this difliculty, I have provided a simple method whereby a strip of material is employed which is about twice the width of that desired tual breaking test. To this I apply a predetermined tension .and then cut or otherwise sever and reduce the cross section of the material to a predetermined dimension, preferably by cuttingthe warp threads at the opposite edges, and then continue the application of the power until the strip is broken, the breaking strain being indicated on a graduated dial, 'By this means the weft threads ,are firmly held by the ends of the interwoven warp threads from raveling or straightening, thus the uncut warp threads of the full remaining inch will hold their original woven shape, and so take their full share of the load permitting an accurate test to-be obtained of the fabric.

In thedrawings I have illustrated one form of' tension applying mechanism in which- 10 and 11 designate, the opposite supports Which are connected together by meansof a plurality of tie rods 12, on the upper pair of which are supported longitudinal rails for the ac- 13 on which roll the two carriages 15 and "this hub is secured a pair of pendulum arms 22 and to the lower portions of these arms is secured an adjustable weight 23 by the screw 24; A gearsegment 25 is also con: nected to this-hub 20 to engage with the pinion 26 and so operate the pointer 27 to indicate in pounds or other unit of measure on a fixed graduated dial,- 28 the amount on the Q of tension which is being: exerted material through the chain 19. On this carriage 15 is mounted a gripping jaw 29 which may be operated by the hand screw 30 and. a duplicate jaw 31 is connected to the carriage 16,its loose jaw being pivoted at 32 and operated by the hand screw 33. ."To the carriage 16 is connected a long tension screw 3a which passesthrough the head 3 in which is mounted suitable mechanism (not shown) whereby the rotating of the hand wheel 36 causes a longitudinal movement of said tension screw. 7 Y

The feature of my present invention is the hand wheel 36 thereby moving both carstrain to have 'a suitable .to be tested are the method or processof subjecting a strip of fabric to a'strain by a testing machine or other suitable device and while under this the yarn or threads at the opposite edges of the strip cut or severed for a given distance inward by hand or'otherwise, whereby the cross section of the material is reduced to a predetermined dimension. I have shown one form of mechanism which may be employed in cutting the edges of the fabric-mechanically which comprises a standard portion 37 adapted to be clamped through the front bar38 to the tie rods 12 and on this standby means of a screw 39 ard I have pivoted at 41 a cutter arm40. This arm blades 42 and 43 which are fastened thereto by screws 44 and 45 and in order to provide support for the material while being cut, I have provided a rest arm 46 which is slotted at 47 and 48 to receive the blades 42 and 43' when the cutter arm descends to force these blades through oppo- 1 siteedges of the material.

1 -.The' following oneform of mechanism employed in the carrying out of my improved method or process describes the operation of ofob'taining the tensile st rength of the material: The opposite ends of the material a' firmly gripped in the jaws- 29 and 31 which spective carriages are mounted on their recally and the pointer 27 indicates zero. The strain is applied to the material by rotating riages to the right and swinging the Weight from its vertical position and when the pointer indicates a predetermined amount the hand of the operator strikes the handle 49'of the knife arm and theblades 42 and severing the edges 43 are forced down through the material of the same inward a predetermined distance. These blades are immediately returned by the spring 50 and the process is continued until the material I breaks at which time the position of. the pointer is accurately noted thus indicating 40"is provided with a pair of its warp made equally as well in the direction of the under tension,

15 and l6.- At the beginning of the test the weight 23 hangs vertithan that to the exact tension in pounds or other unit of measure at which the material was severed. The pendulum' arm 22 is provided with a pawl 51 whi'ch contacts with the notched surface of the segment bar 52 so that this weight and the pointer are caused to remain in theiradvanced position until such time that it is desired to return them to normal which may be accomplished by a small reel 53 operated by the handle 54 to wind up the cord 55 and apply sufficient tension on the arm 56 to release the pawl 51 and then lower the weight back to normal.

- I have describedthe testing strain on the fabric as being applied in the direction of threads but the same test may be weft threads if desire v p 'Iclaimr 1. The improved method of testing the tensile stren h of material consisting in tensioning the material, reducing the material while under tension .to, a predetermined dimension by incisions, and increasing the strain until the material is broken.

2.. The improved method of testing the tensile strength of a strip of material consisting in tensioning the material, cutting each . duce the fabric to a predetermined testing width, and increasing the strain to the desired amount.

In testimony whereof I aflix my in presence of two witnesses. HENRY L. SCOTT.

signature Witnesses:

HOWARD E. BARLOW.

A. F. MACREADY. 

